How to Stop Your Diving Mask from Fogging

There’s nothing worse than slipping into crystal clear water only to find your diving or snorkeling mask slowly fogging up. Instead of enjoying coral reefs or marine life, you’re stuck constantly clearing your mask and trying to see through a cloudy lens. Mask fogging is one of the most common frustrations for divers and snorkelers. Fog forms when warm, moist air inside your mask meets the cooler surface of the lens, causing condensation droplets to appear.

New diving masks and snorkeling masks are especially prone to fogging because manufacturers apply a thin protective silicone film to the inside of the glass during production. While this coating protects the lens during shipping, it also encourages condensation. Fortunately, there are several ways divers and snorkelers deal with mask fog. Some methods work better than others, and newer mask technologies have made the process much easier.

Why Do Diving and Snorkeling Masks Fog Up?

Mask fog happens when warm, moist air from your breath meets the cooler surface of the lens. That temperature difference causes condensation to form tiny droplets on the inside of the glass. Those droplets scatter light and create the familiar cloudy effect that blocks your view.

New diving masks and snorkeling masks are particularly prone to fogging. During manufacturing, a thin silicone film is applied to the inside of the lens to protect the glass during storage and shipping. While that coating protects the mask, it also encourages condensation.

Even once the factory film has been removed, fogging can still happen. Oils from your skin, residue from previous dives, breathing through your nose, or a poorly fitting mask can all contribute to condensation forming on the lens.

How Divers and Snorkelers Stop Mask Fog

Brand New Masks

To remove that leftover film, there are two tried-and-tested methods that every diver will swear by. Remember that only the inside of your mask needs de-fogging; the outside does not.

1. Toothpaste

Yup, plain old toothpaste! Tiny granules help to break down the oil-based lens coating, which you can then just wash away. Make sure you use a gentle, non-whitening toothpaste to protect your mask: the simpler the better. Using your finger or a soft cloth, spread a good dollop of paste around both lenses and leave overnight. Rinse in the morning and hey, presto. This process helps prepare the mask, but it doesn’t prevent fogging permanently.

2. Flame

The second option is to burn the film off. Use the tip of a flame from a lighter on the inside of the mask. Keep the mask moving so that no one spot gets too hot, and you’ll start to see the film turn black. Once both lenses are black, wipe away with a soft cloth and repeat the process once or twice more until the lens no longer blackens. This means that all of the film has been removed.

Important:  this method should only be used on tempered glass lenses, not plastic ones. The flame should also never be held close to the silicone skirt of the mask, which can melt.

Used Masks

Even after the film has been removed, your mask will likely start fogging again over time. Many divers treat their mask before each dive or snorkeling session.

3. Baby shampoo

A diluted baby shampoo solution is a common choice because it’s gentle on the eyes. Place a few drops of watered-down baby shampoo in each lens and spread with your finger, then rinse lightly before your dive. I would always recommend baby shampoo over even a mild dish soap, as I’ve found the latter to be more irritating to the eyes when my mask has leaked.

4. Commercial anti-fog products

You can also buy specialized anti-fog products designed specifically for dive and snorkeling masks. These sprays help create a thin hydrophilic layer on the lens that reduces condensation and keeps your view clear underwater. Simply spritz the inside of the lenses, spread evenly, and rinse lightly before your dive. A small amount of product should remain on the lens to prevent fog from forming. It’s best to choose reef-safe formulas, since harsh chemicals can damage fragile marine ecosystems. Tidal Anti-Fog Spray, for example, uses a reef-safe formula designed for dive masks, snorkel masks, and goggles, and works especially well with Tidal Masks’ advanced anti-fog films. Learn more about our commitment to cleaning up our world’s oceans.

5. Spit!

It might not be glamorous, but saliva has been used by divers for decades. Spit acts as a mild surfactant that helps water spread across the lens instead of forming droplets. Many divers simply spit into their mask, rub it around, and rinse lightly before putting it on.

Author’s Advice: Rinse the saliva out before you put your mask on your head. There’s nothing more upsetting than your own spit oozing down your forehead and into your eyes in front of your dive buddies. Regrettably, I speak from experience…

6. Potato

Yes, really. Some divers swear that rubbing the inside of a mask lens with a freshly cut potato helps prevent fogging. The starch from the potato is said to leave behind a thin anti-fog layer. While it’s not the most convenient option to carry in a dive bag, the trick has been passed around dive boats for years.

Extra Tips for Divers and Snorkelers

7. Avoid nose-breathing

It can be a strange adjustment for some, but breathing solely out of your mouth is essential while diving or snorkeling. Your breath contains moisture, and if a warm breath meets cold glass underwater then you’ll create instant fog.

8. Don’t touch the inside of the lens

Once you’ve cleaned your mask, avoid touching the inside again with your hands. Small bits of dirt and oil may adhere to the inside and stop your chosen anti-fog treatment from working fully.

9. Make sure your mask fits properly

If your mask has any gaps or is too loose, then water will inevitably creep in while you’re underwater. This will require you to clear by breathing out through your nose and inducing foggy lenses as mentioned in tip # 7. If you’re unsure whether your mask fits correctly, check out our guide on how to know if a scuba mask fits properly before your next dive.

Why DIY Defog Methods Eventually Fail

All of the methods above work by leaving a thin film on the lens that reduces surface tension. Instead of forming droplets, moisture spreads into a thin layer across the glass. The problem is that these treatments are temporary. Saltwater, rinsing, and repeated dives gradually wash them away. That means the process needs to be repeated again and again, often before every dive or snorkeling session. For many divers, this becomes part of the routine: apply something to the mask, rinse it lightly, and hope it works for the duration of the dive. Modern anti-fog mask technology takes a different approach.

https://www.youtube.com/watch?v=OgSs08iF-6c

Anti-Fog Diving and Snorkeling Masks

Instead of relying on temporary treatments, some masks now use hydrophilic anti-fog film permanently applied to the inside of the lens. These films spread condensation into an invisible layer across the glass rather than allowing droplets to form. The result is far more consistent fog prevention without needing toothpaste, sprays, or spit before every dive.

Tidal masks use proprietary hydrophilic anti-fog films pre-installed on the inside of the lens. This technology has been part of the mask design since Tidal launched in 2019 and is one of the reasons divers and snorkelers report clear visibility without constant preparation. This approach is different from traditional anti-fog coatings. If you’re curious about the difference, we explain it in more detail in our guide to anti-fog films vs anti-fog coatings.

Choosing the Right Anti-Fog Mask

Fit, comfort, and mask design all play an important role in preventing fogging. Tidal offers several styles designed for different underwater activities. Many snorkelers prefer single-lens masks because they offer a wide field of vision. Dual-lens masks are popular among scuba divers and freedivers because they reduce internal volume and make mask clearing easier.

Freediving masks are designed with a compact shape that allows for easier equalization during deeper dives. Tidal also offers masks with transparent silicone skirts for a brighter field of view, as well as black skirt masks that reduce glare and reflections. There are also masks designed specifically for younger snorkelers, ensuring kids have a comfortable fit and clear underwater visibility.

Across the lineup, each mask uses the same hydrophilic anti-fog film designed to maintain clear lenses throughout your dive or snorkeling session. Tidal Masks are designed to fit nearly 90% of face shapes, and every mask is backed by a 30-day fit guarantee. If the mask doesn’t fit as expected, it can be returned within 30 days as long as the protective film remains intact. Customers also benefit from the two-year manufacturer's warranty.

The performance has been recognized by professionals as well. ScubaLab named the Tidal Single-Lens Mask its “Testers Choice” for 2025, praising the crystal-clear visibility created by the built-in anti-fog film and the mask’s comfortable, secure seal.

Divers and snorkelers report similar experiences in real-world use:

“Wow! I spent hours snorkeling in St. John and this mask did not fog up once. There was not one drop of water in it and it gave the most amazing wide-angle views underwater. This mask made my snorkeling adventure 10/10.”

“I have dived and snorkeled for many years and ProShot’s anti-fog technology makes an amazing difference. It solves the problem of lens fogging better than anything I have ever seen.”

Long-Term Care to Protect Your Diving Mask

It goes without saying that any SCUBA or snorkel gear should be properly cared for if you want to keep it working for as long as possible. Here are some tips for general mask care:

• Rinse your mask thoroughly with fresh water after every dive to remove salt and sand. Clean gently with mild detergent every few dives to remove any oils.

• Never use an abrasive cloth or brush to clean your mask as it may scratch the tempered glass.

• Make sure your mask is completely dry before storing it, as damp materials may start to deteriorate.

• Don’t leave your mask in direct sunlight! If it has any special features like an anti-fog film then the pervasive UV rays may cause degradation over time.

FAQ: Diving and Snorkeling Mask Fogging

Why does my snorkeling mask fog up so quickly?

Snorkeling masks fog when warm air from your breath condenses on the cooler lens surface. Oils, residue, and poor mask fit can also contribute.

How do you stop a snorkeling mask from fogging?

Common methods include toothpaste cleaning, baby shampoo, anti-fog sprays, or saliva. Masks with built-in anti-fog film technology provide the most consistent long-term solution.

Do anti-fog diving masks really work?

Yes. Masks that use hydrophilic anti-fog films reduce condensation by spreading moisture evenly across the lens instead of allowing droplets to form.

How long does anti-fog spray last?

Most sprays only last one or two dives before they need to be reapplied.

How do I make my mask anti-fog?

New masks should first have the factory film removed using methods like toothpaste cleaning or the flame technique (for tempered glass lenses). After that, divers usually apply temporary treatments such as baby shampoo, anti-fog spray, or saliva before each dive. Masks with built-in anti-fog film reduce the need for these treatments, and replacement anti-fog films can be applied later to restore performance if needed.

Cheers to a Fog-Free Future!

Foggy masks are a common frustration for divers and snorkelers, but with the right preparation they’re largely preventable. Traditional tricks like toothpaste, baby shampoo, or anti-fog sprays can help reduce condensation, though they usually need to be reapplied before every dive.

Many divers now choose masks with built-in anti-fog film technology instead. Tidal Masks use proprietary hydrophilic anti-fog films pre-adhered to the inside lens, designed to keep your view clear for months of regular use. And when the film eventually wears down, replacement anti-fog films can be applied easily to restore the mask’s performance without replacing the mask itself. The result is less time defogging your mask and more time enjoying the underwater world.

Shop our Range of Tidal Masks with Advanced Anti-Fog Technology